April 6, 2011
GPS Threatened By New Wireless Network
GPS signals across the U.S. are threatened by a new, ultra-fast wireless Internet network that may interfere with everything from consumer navigation devices to police cars to airplanes, reports the Associated Press (AP).
A government decision to let the satellite company LightSquared build a nationwide broadband network using airwaves next to those used by GPS has led to the problem of a possible jam in existing navigation systems.
LightSquared's roots as a satellite operator have had their airwaves reserved primarily for satellite communications. However, in 2003, FCC rules were changed to allow the company to back up those signals with ground-based wireless to fill in coverage gaps.
The FCC went further in January when LightSquared was given permission to use its airwaves for a broader, more conventional wireless data network. The company will still offer its satellite service, but will also plan to cover at least 92% of Americans by 2015 with high-power wireless signals that are transmitted by base stations on Earth, reports AP's Joelle Tessler.
With LightSquared's super-fast, fourth generation wireless services the company plans to compete nationally with 4G networks being rolled out by companies such as AT&T and Verizon Wireless. However, it will not directly sell to consumers. Instead it will provide network access to companies such as Leap Wireless of Cricket phone service and be rebranding under Best Buy.
By allowing LightSquared to expand its services, the FCC's goal is to boost wireless competition and bring cheaper and faster Internet connections to all Americans, even those in remote locations of the country.
Although the FCC and LightSquared insist that the new network can co-exist with the GPS systems, manufacturers of GPS devices believe that their signals will suffer "the way a radio station can get drowned out by a stronger broadcast in a nearby channel."
They say that the problem will occur when sensitive satellite receivers that are designed to pick up weak signals from space are overwhelmed by LightSquared's high-power signals that are coming from as many as 40,000 transmitters on the ground using airwaves from next door.
"The potential impact of GPS interference is so vast, it's hard to get your head around it," says Jim Kirkland, vice president and general counsel of Trimble Navigation Ltd, which makes GPS systems.
This could mean 40,000 GPS dead spots covering millions of miles in towns and cities throughout the U.S., Kirland told Tessler.
The interference will affect as many as 40% of the commercial and private planes, which depend on the GPS navigation system. The ground-based radio signal backup systems are not as accurate, and have gaps in coverage. And in some older planes, there is no back-up at all.
A spokesperson for the Aircraft Owners and Pilots Association says that with GPS interference, a pilot "may go off course and not even realize it."
Other risks involve public safety. Officials are nervous that the new, stronger signals from LightSquared will interfere with the tracking and dispatching of police cars, fire trucks and ambulances, which all rely on the GPS system. The 911 system depends on GPS to locate people and any disruptions would delay responses to emergencies, Harlin McEwen of the International Association of Chiefs of Polices told AP.
The Pentagon also has expressed its concerns, since it relies on GPS to guide planes, ships, armored vehicles, weapons and troops.
Federal Aviation Administration has a multi-billion-dollar program to upgrade the nation's air-traffic control system that could also be undermined by LightSquared's network.
This multi-billion-dollar project will have a new GPS system that is more precise and will let planes fly on a more direct route. In turn it will save airlines time, money and fuel, and cut down on pollution. In addition, it could help project increases in airline traffic by enabling planes to fly safely closer together.
Before LightSquared can turn on its signals, the FCC is requiring the company to participate in a study group with GPS manufacturers and users and to conduct further testing to determine the extent of any interference.
"We have every reason to resolve these concerns because we want to make sure there is a robust GPS system," says Jeffrey Carlisle, LightSquared executive vice president.
If interference exists, the cost to fix the problem ranges widely.
Dan Hays, a consultant with the firm PRTM, estimates the cost to be about $12 million dollars, which he says, is the cost to install better filters in roughly 40 million standalone GPS units. He says that cellphone will work the same, as they do not rely solely on GPS to determine location and generally have better filters.
However, Tim Farrar from TMF Associates insists that cellphones get upgraded as well as expensive existing equipment, and projects the cost to be near $1 billion.
Scott Burgett, a software engineering manager for Garmin Ltd., told Tessler that GPS receivers were designed to screen out low-power signals next door. Now that the government has changed the rules, GPS manufacturers insist that neither they nor their customers should have to pay to fix the problem.
However, the FCC and LightSquared say that the GPS industry "should have been preparing for a ground-based network nearby since the FCC first allowed backup wireless systems in the space in 2003."
"This is a situation where the neighbor built the fence too far over the property line and may not have realized it at the time," says Hays. "Now the other neighbor wants to build a pool and there is not enough space. So the question is : who has to pay to move the fence?"
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